The sensor data displayed here is collected by
PurpleAir Air Quality
Sensors.
The numerical reports are based on the US EPA PM2.5 Air Quality Index
(AQI). The AQI
is a number used by goverment agencies to communicate how polluted the air currently is or
how polluted
it is forecast to become.
Particulate Matter (PM) 2.5 refers to the pollutants which are 2.5 micrometers or smaller.
Data for Superfund sites can be found here